A Novel Wide Band Microstrip-Line-Fed Antenna With Defected Ground for Cp Operation

Abstract

Abstract-A novel wide band microstrip line-fed antenna with defected ground structure is proposed for circularly polarized characteristics. This antenna is suitable for C-band and partially X-band operation. Antenna1 structure consists of microstrip-line-feed, and the square-shaped slot defect is incorporated in the ground plane. Furthermore, rectangular and circular patches are embedded in the square-shaped slot that improves the performance of the radiating Antenna2 and Antenna3 structures, respectively. The proposed Antenna3 is compact in size and shows a good quality of polarization at resonant frequency band. Antenna3 shows the measured impedance bandwidth of 40.72% (6.45-9.75 GHz) and also shows the variations of 3-dB axial ratio bandwidth at the 6.806 GHz and 9.13 GHz frequencies with the simulated results, respectively. The return loss, axial ratio, gain, efficiency and radiation pattern of the proposed Antenna3 remain consistent for resonant frequency band. The antenna is practically fabricated and simulated. Measured result shows a good agreement with simulated and theoretical ones.

DESIGN ANALYSIS AND MODELING OF DIRECTIONAL UWB ANTENNA WITH ELLIPTICAL SLOTTED GROUND STRUCTURE FOR APPLICATIONS IN C- & X-BANDS

“…Inserting an elliptical slot in a circular patch, the antenna resonates in five modes. The first three resonant frequencies 4.5 GHz, 6.3 GHz, 7.5 GHz cover up C-band, and the last two frequencies 9.3 GHz, 10.8 GHz cover up X-band operation entirely, compared to previously designed antennas [29][30][31][32][33]. The proposed design achieves 95% impedance bandwidth in UWB frequency range 4.10-11.5 GHz.…”

“…The measured results show good agreement with equivalent circuit model and CST simulation. The radiation pattern, impedance bandwidth, directivity and flat gain characteristics of the antenna have also been compared with the earlier suggested similar research work [21][22][23][24][25][26][27][28][29][30][31][32][33]. The radiation patterns of the proposed antenna at different frequencies are shown in Fig.…”

“…17. In Table 4, a comparative study of performance analysis of the designed antenna is given with recently suggested antennas [21,[29][30][31][32][33].…”

“…Impedance bandwidth is 95% (4.1-11.5 GHz) at 4.5 GHz, 6.3 GHz, 7.5 GHz, 9.3 GHz and 10.8 GHz resonance frequencies. Hence, the proposed directional ultra-wideband antenna is appropriate for Cand X-band operations in comparison to previously designed antenna [33].…”

Design of high gain/directional ultra-wideband antenna for radar imaging systems

“…Sharma et al proposed a wideband having 50 × 50 mm 2 substrate size circular ring antenna, which cover the frequency range of 8‐12 GHz with low gain. Recently, the directional UWB antenna is designed with DGS or slotted ground structure for airborne radar, microwave imaging, C, X‐bands operation and compared with other reported antennas but these antennas are large in size . Furthermore, Wang et al designed a bow‐tie directional antenna with pyramidal reflector for UWB radar imaging systems.…”